Prior Art
Textile materials such as woven fabrics utilized in various uses are, generally, simply in sheet form. Therefore, in order to use them for structural materials of three-dimensional construction, sheet-like fabrics have to be interconnected as by sewing or have to be stacked; thus, there has been the problem of maintaining the strength in the joined portions. Even if they are stacked, the resulting stack is lacking in the cushioning property and presents a problem about the heat insulating property. For example, when it is used as a tent or the like, to impart the heat insulating property thereto it has been necessary to laminate thereto a sheet having a heat insulating property.
As for a textile material having a substantial thickness, there is known a double fabric comprising two sheets of raw material, face and back, and connecting portions which connect them by means of double knit or double weave. However, this double fabric, through having a more or less increased thickness, does not have cell-like hollow portions, poor in three-dimensional characteristics, such as heat and noise insulating properties and lightweight feature, there have been problems when it is used in the state in which it is filled with one of various materials.
A so-called honeycomb type blind is known which comprises oblong cylindrical portions of hexagonal or rhombic cross section interconnected in parallel for expansion and contraction like an accordion. However, conventional blinds using sheets such as nonwoven fabrics and paper require a complicated manufacturing process and lack toughness, presenting problems about durability.
Accordingly, it has been contemplated to integrally form a honeycomb type curtain or blind by binding two woven fabrics by two-ply weave at given intervals in the weaving direction to continuously form a number of long parallel cylindrical bag portions through the bound portions in the two woven fabric plies, said bag portions extending in the woven width direction.
In the case of such curtain or blind using two-ply weave, ink order to impart expansibility thereto it is necessary to expand the cylindrical bag portions in the face and back direction, impart creases to the rhombic or hexagonal cross section and then heat-set the same. This creasing treatment requires special bar-like molds, which have to be inserted in the individual cylindrical bag portions, an operation which is very troublesome. From a practical point of view, it is desirable to make it possible to effect this creasing treatment mechanically with ease.
Further, in the case of said curtain or blind by two-ply weave, since the cylindrical bag portions are intermittent through the linear bound portions, lacking in a voluminous feel, the light shielding and heat insulating properties being unsatisfactory